Question: Find an explicit formula for the arithmetic sequence $170,85,0,-85,...$. Note: the first term should be $\textit{d(1)}$. $d(n)=$
Answer: The general explicit formula for arithmetic sequences is ${a_1}+{d}(n-1)$, where ${a_1}$ is the first term and $ d$ is the common difference. The first term is ${170}$ and the common difference is ${-85}$. ${-85\,\curvearrowright}$ ${-85\,\curvearrowright}$ ${-85\,\curvearrowright}$ ${170},$ $85,$ $0,$ $-85,...$ This is the explicit formula for the arithmetic sequence $170,85,0,-85,...$. $d(n)={170}-{85}(n-1)$ Note that this solution strategy results in this formula, however an equally correct solution can be written in other equivalent forms as well.